fix crash in argument unpacking when receiving insufficient keyword arguments

Cython/Compiler/Nodes.py

@@ -2830,7 +2830,7 @@ class DefNode(FuncDefNode):
 
         # If we received kwargs, fill up the positional/required
         # arguments with values from the kw dict
-        code.putln('if (likely((kw_args = PyDict_Size(%s)) > 0)) {' % Naming.kwds_cname)
+        code.putln('kw_args = PyDict_Size(%s);' % Naming.kwds_cname)
         if self.num_required_args or max_positional_args > 0:
             last_required_arg = -1
             for i, arg in enumerate(all_args):
@@ -2937,7 +2937,6 @@ class DefNode(FuncDefNode):
                 self.name))
         code.putln(code.error_goto(self.pos))
         code.putln('}')
-        code.putln('}')
 
     def generate_argument_conversion_code(self, code):
         # Generate code to convert arguments from signature type to

tests/run/argerrors.py

+# mode: run
+
+def test_single_arg(a):
+    """
+    >>> test_single_arg(1)
+    1
+    >>> test_single_arg()                # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_single_arg(1,2)             # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_single_arg(**{})            # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_single_arg(*(), **{})       # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    """
+    return a
+
+def test_two_args(a,b):
+    """
+    >>> test_two_args(1,2)
+    (1, 2)
+    >>> test_two_args()              # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_two_args(1)             # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_two_args(1,2,3)         # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_two_args(**{})          # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_two_args(1, **{})       # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    >>> test_two_args(*(), **{})     # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+    TypeError: ...
+    """
+    return a,b